摘要 |
An electrically operated valve assembly comprises a valve, an electrical device 18 to operate the valve in one direction, and means 19 to prevent reverse current flow if the valve should drive the electrical device in reverse when the valve moves in a direction opposite to the said one direction. In the embodiment shown the valve has a plunger controlled by a cam, the cam being driven by a motor 18. The valve may however also be controlled by a solenoid. |